Acoustic Signal Embedding via Separable Sound Masking

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Solution Overview

Problem

Existing methods for transmitting arbitrary signals using acoustic sounds within audible frequency ranges face challenges such as increased data volume, potential impact on audio quality, and limitations in equipment usage, as well as risks of affecting the mood of the original sound.

Innovation Solution

Embedding an arbitrary signal into the acoustic sound by identifying separable sounds and modifying their additional elements to match the signal pattern, ensuring the signal is transmitted without altering the sound's quality or mood, using techniques like temporal and frequency masking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an arbitrary signal is embedded into the acoustic sound within an audible frequency range, then the signal can be transmitted using general-purpose audio equipment, but the quality or mood of the original acoustic sound may be affected

Engineering Contradiction:
Improvecompatibility with general-purpose audio equipmentVSAvoidimpact on audio quality and mood
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the acoustic sound into multiple frequency bands and identifies specific time-frequency positions where the arbitrary signal can be embedded without affecting the perceived quality. By dividing the sound spectrum and analyzing it in short-time frames, the method locates regions where signal embedding is imperceptible to human ears, thus resolving the contradiction between signal transmission and audio quality preservation.

Inventive Principle:
Principle #1Segmentation

2Loss of information

If an arbitrary signal is embedded into the acoustic sound, then data transmission is achieved, but the data volume increases and dedicated equipment may be required

Engineering Contradiction:
Improvesignal transmission capabilityVSAvoiddata volume
Core Design Contradiction:
Loss of informationVSQuantity of substance

Solution Approach 1:

The patent makes general-purpose audio equipment multi-functional by enabling it to both play audio and transmit arbitrary signals simultaneously through the same audio output channel. The embedding method allows standard speakers and microphones to serve dual purposes: reproducing the acoustic sound while also conveying the hidden arbitrary signal, thereby eliminating the need for dedicated transmission equipment and reducing overall data volume requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If an arbitrary signal is embedded within a frequency range nearly indistinguishable to human ears, then audio quality is preserved, but the position and time for signal insertion are limited

Engineering Contradiction:
Improveaudio quality preservationVSAvoidflexibility in signal insertion
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent employs dynamic analysis of the acoustic sound in the time-frequency domain, continuously identifying suitable embedding positions as the sound evolves. By using short-time Fourier transform and tracking the energy distribution across frequency bands over time, the method adaptively selects optimal insertion points where the arbitrary signal can be placed without compromising audio quality, thus providing flexibility in signal insertion while preserving sound quality.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables the transmission of arbitrary signals within audible frequency ranges without affecting the quality or mood of the original acoustic sound, allowing recognition of the modified sound as equivalent to the original.

Implementation Method 1

using techniques like temporal and frequency masking

Methodology Applied
Scientific EffectTemporal masking:

Implementation Method 2

using techniques like temporal and frequency masking

Methodology Applied
Scientific EffectFrequency masking:

Data Source

PatentEP3128512B1Method for acoustically transmitting an arbitrary signal
Publication Date: 2020.08.26 KARASAWA MASUO
  • EP3128512B1 patent drawingFigure 1~2B
  • EP3128512B1 patent drawingFigure 3
  • EP3128512B1 patent drawingFigure 4A~5

AI summary

To provide a transmission method of an arbitrary signal using an acoustic sound hardly affecting the mood (quality) of the original acoustic sound even if an arbitrary signal within an audible frequency range is combined into the acoustic sound such as music. The method comprises a step of finding a separable sound, of which a fundamental element (fundamental sound) b2 contributing mainly to recognition of a single sound and an additional element contributing collaterally to recognition of the single sound are separable on temporal axis or frequency axis, among plural sounds composing the acoustic sound, or inserting a separable sound into the plural sounds composing the acoustic sound. The additional element of the separable sound found or inserted is transcribed by a signal pattern b1-1, b1-2 of the arbitrary signal. By means of the acoustic sound of which additional element is transcribed, the arbitrary signal b1-1, b1-2 is transmitted. The additional element may be a sound generated when transmitting vibration energy to a resonance body (resonant body). The fundamental element may be a sound produced according the own resonance mode (resonant mode) by the resonance body (resonant body) receiving the vibration energy.